9 KW Mira Sport on 6mm cable

Just had chance to revise this - Simple answer is that we don't have enough information to offer you a safe solution from a screen (so to speak) - also - unless you are a self certifying electrician (can you register under part p?) then you are not permitted to alter any of the systems within special zones, of which a bathroom is one. You need an electrician that is fully insured regulated (napit niceic ect) and capable of registering alterations with part p and providing certification. It is likley that the load will exceed the rating of the the cable (but again we do not have enough information to offer anything more) - and you are in no way qualified to swap out an mcb if you cannot perform basic volt drop and general cable rating calculations on a property - sorry, no offence meant but there is no way to do this safely unless you are as described above and can fully register any alterations. My official advice is DO NOT ATTEMPT THIS OR ANY WORK UNDER THE REQUIREMENTS OF PART P UNLESS YOU ARE REGISTERED, EXPERIENCED AND TRAINED TO DO SO. My reason for being so brusque? If you overload the cable and take away the safety currently built into the design (the 32Amp MCB) and you do not take into account the BS7671 requirements for additional safety (I will not explain these here) then you open up the very real possibility of burning down the property. That is why I advise that you hire a qualified registered electrician.

Hi . A 9 KW Shower will pull 37amps when used so a 40 amp breaker would be sufficient however your cable should realistically be 16 mm on the length of run. That would give you a voltage drop of 1.2 volts . Hope this helps

needs qualified competent electrical engineer and part P to do this , no diversity on a shower etc etc etc

In short NO it’s not suitable

Minimum cable size for this shower should be a 10mm from the fuse box to isolater and isolater to shower and the breaker must be a 40a. This should also be carried out by a qualified electrician.

Get a registered, qualified Electrician to assess & carry out works. This job requires Notifying to LABC under Part P Building Regulations. This is not a DIY task to try & attempt, as you would then be liable for any damage to property or persons. Hope this helps & influences your decision. Steve S.C. Electrical Contractors